Allosteric BDNF-TrkB Signalling as the Target for Psychedelic and Antidepressant Drugs

Allosteric BDNF-TrkB Signalling as the Target for Psychedelic and Antidepressant Drugs

by Prof. Dr. Eero Castrén

Life & Natural Systems Medicine & Health MKGPharmacologyMKGWPsychopharmacology
🎙 Prof. Dr. Eero Castrén 👥 7K 📅 October 4, 2025 ⏱ 36 min 👁 162 📄 expert opinion 🧭 2026-08-16
Available in: English (current) Français

Keywords

BDNFTrkBallosteric modulationpsychedelicsantidepressantsneuroplasticitycritical periodLSDpsilocybinketamine

Summary

In this talk, Prof. Eero Castrén presents his lab’s recent findings on the allosteric modulation of BDNF-TrkB signaling by psychedelics and antidepressants. He explains that BDNF is a central regulator of neuroplasticity, acting on TrkB receptors to stabilize active synapses. His lab discovered that antidepressants, including fluoxetine and ketamine, bind to a novel allosteric site on the TrkB receptor, and that psychedelics like LSD and psilocybin bind with much higher affinity. This binding stabilizes the receptor in the plasma membrane, increasing the probability of BDNF binding and signaling. Using a knock-in mouse with a mutation that prevents drug binding, they show that the antidepressant-like and plasticity-promoting effects of these drugs are mediated by this TrkB site, while the psychedelic experience is mediated by 5-HT2A receptors. They also demonstrate that these drugs reopen critical period plasticity in the visual cortex, and that this plasticity requires concurrent environmental input. The talk concludes with the hypothesis that the therapeutic effects of psychedelics and antidepressants may be separable from the psychedelic experience, and that the drugs’ efficacy depends on the supportive context in which they are administered.

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Critical Evaluation

Value of the Information & Strength of the Argument

The talk provides valuable insights into a novel mechanism of action for psychedelics and antidepressants, potentially shifting the paradigm in the field. The argumentation is solid, based on a series of experiments including binding assays, mutagenesis, behavioral studies, and plasticity models. The speaker carefully distinguishes between the direct effects on TrkB and the 5-HT2A-mediated effects, and emphasizes the importance of environmental input for functional plasticity. The presentation is clear and logically structured, with a strong emphasis on the translational implications.

Scientific Rigor, Source Quality, Title Accuracy

The talk is scientifically rigorous, with the speaker referencing his own published work and collaborations. He acknowledges limitations, such as the lack of human studies and the need for further research. The title accurately reflects the content. The talk is based on expert opinion and recent research findings, but does not provide a comprehensive literature review. The speaker does not cite specific external sources, but the content is consistent with current scientific knowledge.

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Title / Content Match

The title accurately reflects the content, focusing on allosteric BDNF-TrkB signaling as a target for psychedelics and antidepressants.

Quality & Reliability

8/10

The talk is given by a leading researcher in the field, presenting recent findings from his lab, including published and unpublished data. The speaker is transparent about limitations and the need for further research. The claims are mechanistic and supported by experimental evidence, though some extrapolations to humans are speculative.

Key Moments

Markers derived by PSI from the transcript: the creator did not define chapters.

Cited Sources

  • INSIGHT 2023 Replays — The talk is part of the INSIGHT 2023 conference, and the replay bundle is offered for purchase.

Concurring Sources

  • Casarotto et al. (2021) Science — This paper is likely the one mentioned by the speaker, showing that antidepressants bind to TrkB.

Contribution & Novelties

This talk presents a novel mechanism of action for psychedelics and antidepressants, suggesting that they directly bind to the TrkB receptor and allosterically modulate BDNF signaling. This challenges the traditional view that these drugs act primarily through serotonin or NMDA receptors. The findings have significant implications for understanding the therapeutic effects of these drugs and for developing new treatments for depression and other psychiatric disorders.

Pour aller plus loin :

101 words

Radar Profile

The radar profile shows high scores in information quantity, quality, technical level, and reliability, indicating a dense, expert-level presentation with strong scientific backing. The lower score in title adequacy is not reflected in the radar, but overall the talk is highly informative and reliable.

Reliability 8/10

💬 No comments were provided for analysis.